The Ministry of Health convenes a technical advisory committee, the Interagency Committee on the Health Effects of Non-ionising Fields (the Committee), to monitor and review research on the health effects of electromagnetic fields. The Committee reports to the Director-General of Health but also periodically prepares a report for Ministers to provide them with background information and a current summary of key research findings.
This report is not intended to be an exhaustive or systematic review of recent research. Rather, it highlights key findings from comprehensive reviews undertaken in recent years by national and international health and scientific bodies, illustrated in places by examples from individual studies of interest or that exemplify work carried out in particular areas.
The questions over whether exposures to extremely low frequency (ELF) magnetic fields have any effect on the development of leukaemia in children, and neurodegenerative diseases in adults (such as Alzheimer’s disease and amyotrophic lateral sclerosis), remain unresolved. Further studies on childhood leukaemia have not led to any more definitive conclusions on whether the associations between long-term exposure to ELF magnetic fields and childhood leukaemia show a true cause and effect relationship or are simply the results of biases (acknowledged as a possibility), confounding by unidentified factors (less likely), or something else.
This work has confirmed, however, that even if there is some effect of magnetic fields, this would be responsible for only a very low percentage of childhood leukaemias. A comprehensive review by the World Health Organization (WHO) published in 2007 recommended the use of exposure guidelines such as those used in New Zealand, together with very-low-cost measures to reduce exposures where this can be readily achieved. The Committee and the Ministry of Health support these recommendations.
Research into the possible effects of radiofrequency (RF) fields on health also has some open questions. Although studies into brain tumour risks associated with cellphone use have found a small association in the heaviest users, the researchers acknowledge that this could simply reflect biases in the data. Nevertheless, the suggestion that there may be a risk has meant that the International Agency for Research on Cancer (IARC) classified RF fields as a 2B ‘possible’ carcinogen in 2011.*
Animal studies do not suggest an effect of RF fields on cancer. Analysis of brain tumour registrations in relation to numbers of cellphone subscriptions does not show any trends suggesting a link, but this could be due to long latencies, or (perhaps, more improbably) some other factor that is simultaneously acting to reduce brain tumours. Research published since the IARC classification tends to weigh against the possibility of any risk, but may just reflect the fact that exposures from the newer cellphone technologies are much lower than those in use at the time most of the data used in the IARC evaluation was acquired.
RF research is continuing in a number of areas, but data currently available provides no clear or persuasive evidence of any other effects. For this reason, the Committee and the Ministry of Health continue to support the use of exposure limits for RF fields set in the current New Zealand Standard, which is based on guidelines published by an international scientific body recognised by the WHO for its independence and expertise in this area. Those guidelines were first published in 1998 and endorsed, following a review of more recent research, in 2009.
The Committee notes, however, that recent data suggests that at some frequencies the margin of safety may not be quite as high as previously thought. This is not of immediate concern, as public exposures are normally, at most, only small fractions of the allowable limit and a considerable safety margin still remains. However, the Committee recommends that the situation be reviewed following publication of a WHO evaluation of RF fields and health, expected in early 2016.
Much new research has been published since 2004, when the Committee last prepared a report for Ministers, but none of this causes the Committee to consider that current policies and recommendations should be reviewed.
In view of the continuing public interest in this area, the ubiquitous nature of exposures and the open research questions that remain, the Committee will continue to monitor new research.